[trunk][patch] fix invalid sharing in see

[trunk][patch] fix invalid sharing in see

[Rafael Espindola]

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The attached patch fixes an invalid rtl sharing in see. A test is
attached, to reproduce run on a x86_64

./cc1plus -fsee -O2 test.ii

I would like to add test.ii to the testsuite. Where should it go?

OK if bootstraps and regression tests are OK?

* see.c (see_pre_insert_extensions): Use copy_rtx to avoid invalid rtx sharing.

Cheers,
-- 
Rafael Avila de Espindola

Google Ireland Ltd.
Gordon House
Barrow Street
Dublin 4
Ireland

Registered in Dublin, Ireland
Registration Number: 368047

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diff --git a/gcc/see.c b/gcc/see.c
index 6e5260b..8002cde 100644
--- a/gcc/see.c
+++ b/gcc/see.c
@@ -1687,7 +1687,7 @@ see_pre_insert_extensions (struct see_pre_extension_expr **index_map)
 
 		start_sequence ();
 		emit_insn (PATTERN (expr->se_insn));
-		se_insn = get_insns ();
+		se_insn = copy_rtx (get_insns ());
 		end_sequence ();
 
 		if (eg->flags & EDGE_ABNORMAL)

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bool f(const char* ptr, int bar) {
  return (((const char *)0 - ptr ) & (bar - 1)) == 0;
}


int g(const char* ptr, const char *test, int N, int bar)  {
  if (N == 0) {
  }
  else if (N > 0) {
    int count = 0;
    while ( count < N) {
      if (!f(ptr, bar))
        count++;
    }
  }
  return f(test, bar) ;
}

Re: [trunk][patch] fix invalid sharing in see

[Rafael Espindola]

> OK if bootstraps and regression tests are OK?

bootstraps and regression tests pass.

Cheers,
-- 
Rafael Avila de Espindola

Google Ireland Ltd.
Gordon House
Barrow Street
Dublin 4
Ireland

Registered in Dublin, Ireland
Registration Number: 368047

Re: [trunk][patch] fix invalid sharing in see

[Ian Lance Taylor]

"Rafael Espindola" <espindola@google.com> writes:

> diff --git a/gcc/see.c b/gcc/see.c
> index 6e5260b..8002cde 100644
> --- a/gcc/see.c
> +++ b/gcc/see.c
> @@ -1687,7 +1687,7 @@ see_pre_insert_extensions (struct see_pre_extension_expr **index_map)
>  
>  		start_sequence ();
>  		emit_insn (PATTERN (expr->se_insn));
> -		se_insn = get_insns ();
> +		se_insn = copy_rtx (get_insns ());
>  		end_sequence ();
>  
>  		if (eg->flags & EDGE_ABNORMAL)


This should be:
    start_sequence ();
    emit_insn (copy_insn (PATTERN (expr->se_insn)));
    se_insn = get_insns ();
    end_sequence ();

That patch is approved if it passes bootstrap and testing.

The test case should go into gcc/testsuite/gcc.c-torture/compile.  If
there is no PR number, then the name should be DATE-1.c.  See the
other files in that directory.

Don't forget the ChangeLog entry.

Thanks for tracking this down.

Ian

Re: [trunk][patch] fix invalid sharing in see

[Eric Botcazou]

> The attached patch fixes an invalid rtl sharing in see. A test is
> attached, to reproduce run on a x86_64
>
> ./cc1plus -fsee -O2 test.ii
>
> I would like to add test.ii to the testsuite. Where should it go?

There is a couple of problems:

- the testcase is in testsuite/gcc.c-torture/compile but it uses dg-options
so it gets compiled multiple times for little benefit (see the log file).
I think it ought to be in gcc.dg instead.

- the testcase doesn't pass with RTL checking on x86:
/home/eric/svn/gcc/gcc/testsuite/gcc.c-torture/compile/20080522-1.c: In 
function 'g':
/home/eric/svn/gcc/gcc/testsuite/gcc.c-torture/compile/20080522-1.c:20: 
internal compiler error: RTL check: expected code 'subreg', have 'pc' in 
see_get_extension_data, at see.c:735
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

-- 
Eric Botcazou

Re: [trunk][patch] fix invalid sharing in see

[Ian Lance Taylor]

Eric Botcazou <ebotcazou@adacore.com> writes:

> - the testcase is in testsuite/gcc.c-torture/compile but it uses dg-options
> so it gets compiled multiple times for little benefit (see the log file).
> I think it ought to be in gcc.dg instead.

Ah, you're right, sorry.

Ian

Re: [trunk][patch] fix invalid sharing in see

[Rafael Espindola]

2008/5/23 Ian Lance Taylor <iant@google.com>:
> Eric Botcazou <ebotcazou@adacore.com> writes:
>
> Ah, you're right, sorry.

I left trunk bootstrapping with --enable-checking at work. Will try to
fix the problem and move the test in a moment.

> Ian
>

Cheers,
-- 
Rafael Avila de Espindola

Google Ireland Ltd.
Gordon House
Barrow Street
Dublin 4
Ireland

Registered in Dublin, Ireland
Registration Number: 368047